How do i calculate profit/ loss in selling stock?

I need to know how to calculate the profit or loss if i sold all my shares of stock. this is again, for a project, and its THI (Tim Horton) stock. If i bought $1000 dollars worth of stock on May 3rd, 2006 when the price was $28.78 and sold all of it on December 10th of 2008 where the price was $25.77